The present invention relates to an ignition control system for an internal combustion engine adapted to judge that the ignition control system is defective if a clock pulse is not outputted from an oscillator.
An induction discharge type igniter used for an internal combustion engine has incorporated an ignition control system for controlling the energizing timing of an ignition coil due to the development of recent electronic circuit technique.
An ignition control system for calculating the energizing timing of an ignition coil according to a clock pulse outputted from an oscillator by a digital circuit has been proposed as disclosed, for example, in Japanese Patent Laid-open No. 40141/1978.
However, if the clock pulse is not outputted from the oscillator due to certain cause in this ignition control system, the calculation of the energizing time is paused to stop the intermittently interrupting operation of the ignition coil. As a result, there arises a problem that an internal combustion engine is not ignited to stop rotating of the engine.